Summary of Work: We are collaborating with researchers from the National Institute of Diabetes and Digestive and Kidney Diseases and the American Dental Association of the risk of end stage renal disease among dentists exposed to mercury and nitrous oxide. We are comparing 138,000 U.S. dentists who graduated before 1977 with the U.S. renal disease registry to see whether general dentists who are highly exposed to mercury have higher rates of renal failure than orthodontists and other subspecialties who have lower exposures. We will also look whether oral surgeons and pedodontists who have elevated nitrous oxide exposures have increased rates. Dr. Bjorkman, Dr. Sandler, and I are analyzing data from NHANES I to look at the relationship between the number of dental amalgams in a person's mouth and their diastolic blood pressure. The hypothesis is that like lead, mercury might disrupt renal function and increase the risk of hypertension. We are also looking at whether the number of amalgams in a person's mouth increases their risk of poor mental health. In response to our earlier epidemiologic findings, Dr. Davis and Dr. Morgan have begun a series of experiments on the time course of endocrine disruption in rats exposed to mercury vapor. The primary question is whether the mechanism is more likely to involve direct ovarian toxicity or disruption of the hypothalamic-pituitary axis.